Feature/put serve behind feature flag (#455)

* Add build-time feature flag capabilities

* Toggle `bw serve` command with `serve` flag

* Run linter and prettier

config/config.js

@@ -0,0 +1,30 @@
+function load(envName) {
+  return {
+    ...loadConfig(envName),
+    ...loadConfig("local"),
+  };
+}
+
+function log(configObj) {
+  const repeatNum = 50;
+  console.log(`${"=".repeat(repeatNum)}\nenvConfig`);
+  console.log(JSON.stringify(configObj, null, 2));
+  console.log(`${"=".repeat(repeatNum)}`);
+}
+
+function loadConfig(configName) {
+  try {
+    return require(`./${configName}.json`);
+  } catch (e) {
+    if (e instanceof Error && e.code === "MODULE_NOT_FOUND") {
+      return {};
+    } else {
+      throw e;
+    }
+  }
+}
+
+module.exports = {
+  load,
+  log,
+};